Development of a self-monitoring graft is the long term goal of this project. Such a graft, rather than being a passive conduit for blood, would measure the blood flowing through it and, if the flow approached levels at which the graft might thrombose, communicate the need for treatment directly to the physician. At present, 60,000 artificial by-pass leg grafts per year are implanted in the USA. Most fail within three years,leading to amputation. By making such grafts "smart grafts" that communicate impending failure, many of these limbs should be saved. Special ultrasound transducers have been developed that can be embedded in the walls of the graft and measure the blood flow passing through the graft. The proposed Phase I work would demonstrate the feasibility of the smart graft by constructing an operating graft with flow-sensing capability, and by analysis show that the associated circuitry and power source could be implanted with 5 year or more life. The Phase II continuation of the program would undertake the fabrication and implantation of prototype smart grafts.